This invention relates to a semiconductor device, and more particularly to a semiconductor device provided with status detecting function.
For example, in a vertical channel type FET(field effect transistor), detection of drain current or detection of chip temperature is known as a means for detecting abnormal status. Thus, an abnormality of electric characteristic or temperature rise in an ON state of a semiconductor device is detected to protect against property degradation or damage of the device.
But, in heretofore known semiconductor devices, there are no built-in detector for detecting abnormalities in an OFF state of a semiconductor device. Aluminum lead wires, for example, are liable to be slid on a substrate from heat cycles repeated in ages, and are short circuited with other lead wires. In heretofore known semiconductor devices, such a short circuit can not be predicted.
In a MOSFET, an output electrode is placed in the central part of the MOSFET, and a channel stopper is formed around the boundary of the MOSFET. An aluminum electrode connected to the channel stopper is supplied by a power supply voltage in order to bias the channel stopper layer at a proper voltage level. This aluminum electrode is apt to be slid toward the center and the power supply voltage is impressed to the output electrode.